Rigid Body Element, Form 2
Description: Defines a rigid body whose independent degrees of freedom are specified at a single grid point and whose dependent degrees of freedom are specified at an arbitrary number of grid points.
Format:
Example:
| Field | Definition | Type | Default |
|---|---|---|---|
| EID | Element identification number. | Integer > 0 | Required |
| GN | Identification number of grid point to which all six independent degrees of freedom for the element are assigned. | Integer > 0 | Required |
| CM | Component numbers of dependent degrees of freedom in the global coordinate system of grid point GN at grid points GMi . (Up to six unique digits may be placed in the field with no embedded blanks.) | 1 ≤ Integers ≤ 6 | Required |
| GMi | Grid point identification numbers at which dependent degrees of freedom are assigned. | Integer > 0 | |
| A | Thermal expansion coefficient. | Real or blank | 0.0 |
Remarks:
- The components indicated by CM are made dependent at all grid points GMi.
- By default, a dependent degree of freedom assigned by one element cannot be assigned dependent by another rigid element or MPC entry and cannot be additionally constrained (e.g., single-point constraint). If this behavior is desired, use PARAM, AUTOFIXRIGIDSPC which when set to ON will allow the constraint of dependent degrees of freedom. (See Section 5, Parameters, for more information on AUTOFIXRIGIDSPC.)
- Degrees of freedom declared to be independent by one rigid body element can be made dependent by another rigid body element or by a multipoint constraint.
- Rigid elements, unlike MPCs, are not selected through the Case Control Section.
- Forces of multipoint constraint may be recovered with the MPCFORCES Case Control command.